Regulation of Flavonoids Biosynthesis Participating in the Picotee Color Formation of Eustoma grandiflorum

Abstract

We analyzed picotee petals composed of colored and white tissues in order to understand activation/inactivation mechanism of the flavonoids biosynthesis in Eustoma grandiflorum. As for the tip-colored variety, flavonoids were accumulated only in the tip tissue and not accumulated in the white tissue throughout the petal growth. As for the base-colored variety, flavonoids were accumulated in the whole tissue in early stage of petal growth and decreased only in the white tissue with the petal growth progress. Furthermore chalcone synthase (CHS) gene transcription was specifically inactivated in the white tissues of opened petals in both varieties. CHS expressions should be responsible for picotee color formation of E. grandiflorum. The flavonoids accumulation profiles suggest that different mechanisms of CHS gene expression might operate between the tip-colored and the base-colored varieties.